API Ca test kit, good or bad?
 

I was under the impression that this is a good kit, with very accurate and consistent results. I'm currently in conversation with a fellow reefer, on another board, who says that not only is the kit of poor quality, but he gets skewed readings between 3 different API Ca test kits. His own, his buddy's and the LFS's. Personally, I think he is experiencing some sort of user error.

I love this kit, and find it very consistent, accurate, and user friendly. I currently have 3 kits here at the house, and all of them reed the same. Needless to say I am a little dumbfounded by this gentleman's opinions and experiences with the API Ca kit. Maybe I'm alone, and this kit really is of poor quality?

Please post your experiences with the API Ca kit, good or bad.

Also, if anyone has a link to the comprehensive study of all the major test kit manufacturers that was completed by a group of reefers from RC that would be great. I used to have it bookmarked but a PC crash erased it and I haven't been able to find it since :(

Well just this month i am finding my api test kit is not reading accurate i have tried new bottles and my seachem test is reading different then api and im not sure which is correct but i did learn that the cal test kit does not actually test your cal its testing something else that coinsides with the levels of cal in your tank. But the experts here could explian that part better than me.

My API calcium kit tests right in line with my Salifert kit. Also, my API alkalinity test kit always matches my Seachem kit. API makes the best kits I ever used. Maybe they expire before people can use them, or maybe people don't shake the right bottles. I never had a test kit expire but it must be frustrating because they are not properly marked for expiration. Just use them fast, inside of a year should be good for kits without a printed expiration date.

Just bought a new API Cal kit and it reads 500. I was using real natural saltwater from the Gulf of Mexico so rechecked with my trusty salifert kit and measured 440 which is the norm. Gotta return the API kit for a refund. But used another batch of the API cal. test before and it was dead on with Saliferts and much easier and quicker for me to use as the color change is easier for me to pick up.

My ATI kit consistently reads 10-20ppm higher than my Salifert and sometimes as high as 30ppm higher than my Elos. I really in the end have come to trust the Elos. A month or so ago, I stopped dosing any Ca at all for 4 days, and Elos said 400ppm, and ATI said 430ppm, which was only a 10ppm drop from it's previous reading, 5 days ago. And I know in 5 days that my tank is using more than 10ppm of Ca...